RU2665510C1 - Method for producing multilayered paint system - Google Patents

Abstract

FIELD: paint industry.

SUBSTANCE: present invention relates to a process for producing a multilayer paint system on a metal substrate, where the base coating or several directly applied base coatings are directly produced on a metal substrate coated with hardened electroplating, a coating lacquer is applied directly to one base coating or to the uppermost of several base coatings, and then one or more base and varnish coatings cure together, and wherein at least one base coating material that is used to make the base coatings comprises at least one unbranched hydroxy-functional reaction product (R) which has an acid number that is less than 20 mg KOH/g, which comprises using at least one compound (v) comprising two functional groups (v.1) and an aliphatic or araliphatic hydrocarbyl radical (v.2), which is located between the functional groups and has 12 to 70 carbon atoms.

EFFECT: improved quality of coatings.

16 cl, 3 dwg, 6 tbl

Description

The present invention relates to a method for producing a multilayer paint system, where the base coat or several directly applied to each other base coatings are obtained directly on a metal base coated with hardened plating, while a coating varnish is applied directly to one base coating or to the top of several base coatings, and then one or more basecoats and topcoat harden together. The present invention further relates to a multilayer ink system, which was obtained by the method in accordance with the invention.

Multilayer colorful systems on metal bases, for example multilayer colorful systems in the automotive industry, are known. As a rule, multilayer colorful systems of this type contain, when viewed from the side of the metal base, an electroplated coating, a layer that has been applied directly to the electroplated coating, and is usually referred to as a filler primer coating, at least one coating that contains colored pigments and / or effective pigments, and which is usually referred to as a base coat and topcoat.

The basic compositions and functions of these layers and coating compositions necessary for the formation of these layers, i.e. electroplating materials, the so-called filler primers, coating compositions that contain colored pigments and / or effective pigments, and are known as base coat materials, as well as coating materials, are known. For example, electrophoresis electroplating essentially serves to protect the substrate from corrosion. The so-called filler-primer coating serves mainly to protect against mechanical stress, for example, from impacts of small stones, and also to smooth out unevenness on the basis of. The next coating, which is referred to as the basecoat, is mainly responsible for the formation of aesthetic properties, such as color and / or visual effects, such as a flop effect, while the topcoat, which then follows, in particular serves to give a multilayer colorful scratch and gloss resistance system.

These multilayer colorful systems are usually obtained, first of all, by applying or deposition of electroplating, in particular cathodic electroplating, using electrophoresis, on a metal base, for example, a car body. Prior to the deposition of electroplating, the metal base can be pretreated in various ways; for example, it is possible to apply known conversion coatings, such as phosphate coatings, in particular zinc phosphate coatings. The deposition process typically occurs in suitable electrodeposition baths. After application, the coated substrate is removed from the bath, optionally washed and self-vaporized and / or subjected to intermediate drying, and the applied plating finally hardens. The predetermined film thickness is approximately 15-25 micrometers. After that, the so-called putty primer is applied directly to the hardened plating, it is optionally subjected to self-evaporation and / or intermediate drying, and then it is allowed to harden. In order for the hardened primer coating to fulfill the above tasks, the specified film thickness should be, for example, 25-45 micrometers. After that, the hardened primer coating is directly coated with the so-called base coat, which contains colored pigments and / or effective pigments, and is optionally self-vaporized and / or intermediate dried, and the base coat thus obtained is directly applied without separate curing integumentary varnish. After that, the base coat and topcoat, which is optionally also subjected to self-evaporation and / or intermediate drying, are hardened together (wet coating method without preliminary drying). While the hardened base coat basically has relatively low film thicknesses of, for example, 10-30 micrometers, the predetermined film thickness of the hardened coating varnish is, for example, 30-60 micrometers, in order to achieve the described performance properties. Putty primer, base coat and topcoat can be applied by application methods known to those skilled in the art, for example by pneumatic application and / or electrostatic spray application. Currently, putty primers and basecoats are increasingly being used as water-based coatings, at least from an environmental point of view.

Multilayer colorful systems of this type and methods for their preparation are described, for example, in DE 19948004 A1, line 37 of page 17 - line 22 of page 19, or in DE 10043405 C1, paragraph [0018] column 3 and paragraph [0052] column 8 - paragraph [ 0057] column 9, together with paragraph [0039] of column 6 - paragraph [0050] of column 8.

Even despite the multilayer colorful systems obtained in such a way, which, as a rule, can meet the requirements of operational properties and aesthetic characteristics put forward in the automotive industry, nevertheless, simplification of the described relatively complex method of their production, from the point of view of environmental protection and economic reasons, is currently the subject of increasing attention from car manufacturers.

For example, there are approaches in which an attempt is made to dispense with a separate curing step of the coating composition applied directly to the hardened plating (coating composition, which in the context of the above standard method is referred to as putty primer), and also at the same time reduce the thickness of the film obtained by applying the specified coating composition. In the specialized field, said coating film, which as a result does not harden separately, is often referred to as a base coat (and no longer as a filler primer), or as a first base coat, as opposed to a second base coat that is applied to it. There are even some attempts to completely dispense with the specified coating film (in which case only the so-called base coat is obtained directly on the plating, which is coated with a topcoat without a separate curing step from above, which means that in the end they also dispense with a separate curing step). Instead of a separate cure step and an additional final cure step, therefore, there is only a final cure step after applying all the coating films deposited on the plating.

In particular, skipping a separate curing step of the coating composition applied directly to the plating is very advantageous from an environmental point of view and for economic reasons. As a result, this leads to energy savings, and, of course, the overall manufacturing process can occur much more accurately and faster.

Thus, it is preferable that instead of a separate curing step, the coating film obtained directly on the electroplated coatings undergo only self-evaporation at room temperature and / or intermediate drying at elevated temperatures, without carrying out the curing process, which is known to constantly require elevated temperatures curing and / or prolonged cure time.

However, the present problem is that often the necessary operational and aesthetic characteristics cannot be obtained during the specified type of manufacture.

A persistent problem with multilayer paint systems in the automotive industry is that impact resistance, which is a very important characteristic, especially for car paint systems, is not always achieved.

Impact resistance refers to the mechanical resistance of a coating to rapid deformation. In this context, resistance to chips from impacts of small stones is particularly relevant, which means the resistance of the colorful system to small stones that hit the surface of the colorful system with high speed. At the same time, automotive colorful systems are subjected to such impacts of small stones in a very intense degree.

This problem is particularly noticeable in multi-layer paint systems in which the primer coating is completely absent, or which have only a very thin primer coating.

An additional factor is that now the replacement of organic solvent based coating compositions with water based coating compositions is becoming even more important due to the increasing environmental safety requirements.

Accordingly, it would be advantageous to have at its disposal a method for producing multilayer paint systems where, with respect to the coating composition applied directly to the electroplating, it is possible to dispense with a separate curing step as described above, and so that the resulting multilayer paint system, however, has an excellent impact resistance.

The problem that was solved with the help of the present invention, respectively, was to find a method for producing a multilayer paint system on metal substrates, where the coating composition applied directly to the plating does not solidify separately, and where instead, the coating composition solidifies in a joint curing step together with additional coating films applied subsequently. Despite this simplification of the method, the resulting multi-layer colorful systems should have excellent impact resistance, so that the multi-layer colorful systems, in particular, meet the high requirements of automobile manufacturers and their consumers regarding the performance properties of the multi-layer paint system. At the same time, the coating composition, which is applied to the hardened plating, but before the coating varnish material is applied, must be water-based in order to satisfy the increasing environmental requirements of the paint systems.

It was found that these problems are solved using a new method for producing a multilayer paint system (M) on a metal base (S), including

(1) obtaining, on a metal basis (S), a hardened plating (E.1) by electrophoretic deposition of a plating (e.1) onto a substrate (S) and subsequent curing of the plating (e.1),

(2) obtaining (2.1) a base coat (B.2.1) or (2.2) of several base coatings directly applied to each other (B.2.2.x) directly on the hardened plating (E.1) using (2.1) applying an aqueous material the base coating (b.2.1) directly on the plating (E.1) or (2.2) applying several materials of the base coating (b.2.2.x) on each other directly on the plating (E.1),

(3) obtaining a topcoat (K) directly on (3.1) the basecoat (B.2.1) or (3.2) the topmost basecoat (B.2.2.x) by applying the topcoat (k) material directly to (3.1) base coat (B.2.1) or (3.2) the topmost base coat (B.2.2.x),

(4) co-curing (4.1) the base coat (B.2.1) and the topcoat (K) or (4.2) the base coat (B.2.2.x) and the topcoat (K),

Where

the basecoat material (b.2.1) or at least one of the basecoat materials (b.2.2.x) contains at least one unbranched hydroxy-functional reaction product (R) that has an acid number of less than 20 mg KOH / g , the manufacture of which includes the use of at least one compound (v) containing two functional groups (v.1) and an aliphatic or araliphatic hydrocarbyl radical (v.2), which is located between the functional groups and has 12-70 carbon atoms.

The above method is also referred to below as the method in accordance with the invention, and accordingly forms part of the subject of the present invention. Preferred embodiments of the method in accordance with the invention can be found in the following description and in the dependent paragraphs.

The present invention also provides a multilayer ink system, which was obtained using the method in accordance with the invention.

The method in accordance with the invention enables the manufacture of multilayer paint systems without a separate stage of curing of the coating film obtained directly on the plating. For clarity, in the context of the present invention, said coating film is referred to as a base coating. Instead of separately curing, said base coat hardens along with any additional base coat under the topcoat and topcoat. Despite this, the application of the method in accordance with the invention leads to multilayer paint systems that have excellent adhesion under conditions of impact of small stones. It is further possible to obtain appropriate basecoats with water-based coating compositions, thereby satisfying environmental requirements.

First of all, some terms used in the present invention will be explained.

Of course, the same principle applies to the application of coating compositions located directly on top of each other, or to the production of coating films located directly on top of each other.

The application of a coating composition to a base, or the preparation of a coating film on a base, is understood as follows. An appropriate coating composition is applied so that the resulting coating film is positioned on the substrate, but does not need to be in direct contact with the substrate. Between the coating film and the base, for example, other layers may also be located. For example, in step (1), a hardened plating (E.1) is obtained on a metal base (S), but as described below, a conversion coating, such as a zinc phosphate coating, can also be placed between the substrate and the plating.

The same principle applies to applying a coating composition (b) to a coating film (A) obtained by applying another coating composition (a), or to obtaining a coating film (B) on another coating film (A) located, for example, on metal base (S). The coating film (B) does not have to be in contact with the coating layer (A), but simply must be located above it, i.e. on the side of the coating film (A) facing away from the metal base.

In contrast, applying the coating composition directly to the substrate, or preparing the coating film directly to the substrate, is understood as follows. The corresponding coating composition is applied so that the resulting coating film is positioned on the substrate and is in direct contact with the substrate. In particular, therefore, no other layer is disposed between the coating film and the substrate. Of course, the same applies to applying the coating composition (b) directly to the coating film (A) obtained by applying another coating composition (a), or to producing the coating film (B) directly on another coating film (A) located for example, on a metal base (S). In this case, the two coating films are in direct contact, i.e. are located directly above each other. In particular, there is no additional layer between the coating films (A) and (B).

Of course, the same principle applies to the application of coating compositions located directly on top of each other, or to the production of coating films located directly on top of each other.

In the context of the present invention, “self-evaporation,” “intermediate drying,” and “curing” are understood to mean the meanings known to one skilled in the art in connection with methods for producing multilayer ink systems.

Thus, the term “self-evaporation” is, in principle, understood as a term meaning evaporation, or promoting evaporation, of organic solvents and / or water in a coating composition applied during the manufacture of the ink system, usually at ambient temperature (i.e. room temperature). temperature), for example 15-35 ° C for a period that is, for example, 0.5-30 minutes During the self-evaporation process, organic solvents and / or water, which are present in the coating composition thus applied, evaporate. Since the coating composition is still fluid, at least immediately after application and at the beginning of the self-evaporation process, it may become blurred during the self-evaporation process. For this reason, at least the coating composition applied by spraying is typically applied in the form of drip spraying and not in the form of a uniform thickness. However, it is fluid as a result of the presence of organic solvents and / or water, and thus, as a result of fading, it can form a uniform, smooth coating film. At the same time, organic solvents and / or water gradually evaporate, so that a relatively smooth coating film is formed after the self-evaporation phase containing less water and / or solvent, compared with the applied coating composition. However, after the self-evaporation process, the coating film is still not in a state ready for use. For example, it is no longer fluid, but still soft and / or sticky, and in some cases only partially dry. In particular, the coating film is still not hardened, as described below.

Thus, intermediate drying is also understood as one which means evaporation, or promoting evaporation, of organic solvents and / or water in a coating composition applied during the manufacture of the ink system, usually at a temperature elevated relative to ambient temperature, for example, at a temperature which is 40-90 ° C. over a period which is, for example, 1-60 minutes. Also during the intermediate drying process, the applied coating composition will thus evaporate a certain proportion of organic solvents and / or water. As for the specific coating composition, as a rule, in the case of intermediate drying, which occurs, for example, at higher temperatures and / or over a longer period of time, compared to self-evaporation, a higher proportion of organic solvents and / or water, compared to self-evaporation. In this case, intermediate drying does not lead to a coating film in a state ready for use, i.e. hardened coating film as described below. A typical sequence of self-evaporation and intermediate drying processes will include, for example, self-evaporation of the applied coating film at ambient temperature for 5 minutes, and then intermediate drying at 80 ° C for 10 minutes. However, any unambiguous distinction between the two terms is not required and is not meant. These terms are used only for clarification, in order to make it clear that the curing process described below can be preceded by alternating and sequential conditioning of the coating film, where, depending on the coating composition, evaporation temperature and evaporation time, a higher or lower proportion of organic solvents and / or water that are present in the coating composition. As a special case, a certain proportion of the polymers that are present as binders in the coating compositions may be crosslinked or crosslinked, even at this early stage, as described below. However, neither the self-evaporation process nor the intermediate drying process results in a ready-to-use coating film, as is achieved by curing, as described below. Accordingly, curing is clearly distinguished from self-evaporation and intermediate drying processes.

Accordingly, the curing of the coating film is understood as such, which means the transformation of such a film into a ready-to-use state, i.e. in a state in which the substrate provided with the appropriate coating film can be transported, stored and used as intended. In particular, the hardened coating film is no longer soft or sticky, but has been brought to the physical state of a solid coating film that does not experience any additional significant changes in its characteristics, such as hardness or adhesion to the substrate, even under conditions of additional exposure to curing conditions as described below.

As is well known, coating compositions can, in principle, solidify physically and / or chemically, depending on the components present in them, such as binders and crosslinking agents. In the case of chemical curing, possible options are thermochemical curing and actinochemical curing. In the case of thermochemical curing, the coating composition may self-crosslink and / or crosslink under the influence of external factors. The statement that the coating composition is self-crosslinking and / or crosslinking under the influence of external factors, in the context of the present invention, should be understood as one which means that said coating composition contains polymers as binders and optionally crosslinking agents that can suitably crosslink with each other friend. The underlying mechanisms as well as the binders and crosslinkers used are described below.

In the context of the present invention, “physically curable” or the term “physical cure” means the formation of a hardened coating film as a result of the release of solvent from polymer solutions or polymer dispersions, wherein curing is achieved by crosslinking the polymer chains.

In the context of the present invention, “thermochemically curing” or the term “thermochemical curing” means crosslinking that is caused by a chemical reaction of reactive functional groups, a paint film (formation of a hardened coating film), it is possible to provide activation energy for said chemical reactions using thermal energy . The above may include the reaction of different, mutually complementary functional groups with each other (complementary functional groups) and / or the formation of a hardened layer as a result of the reaction of autoreactive groups, i.e. functional groups that react with groups of the same type. Examples of suitable complementary reactive functional groups and self-reactive functional groups are known, for example, from German patent application DE 19930665 A1, line 28 page 7 - line 24 page 9.

Said crosslinking may be self-crosslinking and / or external crosslinking. If, for example, complementary reactive functional groups are already present in an organic polymer that is used as a binder, for example, polyester, polyurethane or poly (meth) acrylate, then self-crosslinking takes place. External crosslinking occurs, for example, when the (first) organic polymer, including certain functional groups, for example hydroxyl groups, is reacted with a crosslinking agent known per se, for example a polyisocyanate and / or melamine resin. Thus, the crosslinking agent contains reactive functional groups complementary to the reactive functional groups present in the (first) organic polymer, which is used as a binder.

In particular, in the case of external crosslinking, one-component and multicomponent systems, in particular two-component systems known per se, are useful.

In one-component systems, the components to be crosslinked, for example, organic polymers as binders and crosslinking agents, are present alongside each other, i.e. as a single component. A prerequisite for this is that the components to be crosslinked react with each other, i.e. enter the curing reaction only at relatively high temperatures, which are, for example, above 100 ° C. Otherwise, the components to be crosslinked should be stored separately from each other and mixed with each other only immediately before application to the substrate, in order to prevent premature, at least partial thermochemical curing (see two-component systems). An example of a combination is hydroxy-functional polyesters and / or melamine resins and / or blocked polyisocyanates as crosslinking agents.

In two-component systems, the components to be crosslinked, for example, organic polymers as binders and crosslinking agents, are present separately, at least in the form of two components that are combined only immediately before application. The specified shape is chosen when the components to be crosslinked react with each other even at ambient temperatures or slightly elevated temperatures, which are, for example, 40-90 ° C. An example of a combination are hydroxy-functional polyesters and / or polyurethanes and / or poly (meth) acrylates with free polyisocyanates as crosslinking agents.

It is also possible when the organic polymer as a binder has both self-crosslinking and externally crosslinkable functional groups, and then it is combined with crosslinking agents.

In the context of the present invention, “actinochemically cured” or the term “actinochemical curing” is understood to mean that curing is possible as a result of application of curing actinic radiation, namely electromagnetic radiation, such as radiation in the near infrared region (NIR) ) and UV radiation, in particular UV radiation, as well as particle radiation, such as electron beams. UV curing is usually caused by radical or cationic photoinitiators. The traditional actinically curable functional groups are carbon-carbon double bonds, for which, as a rule, free radical photoinitiators are used. Thus, actinic curing is also based on chemical crosslinking.

Of course, during the curing of the coating composition described as chemically curing, physical curing is also always possible, i.e. crosslinking polymer chains. However, in this case, such a coating composition is described as chemically cured.

From the above it follows that, depending on the nature of the coating composition and the components present in it, curing is caused by different mechanisms, which, of course, also require different conditions during curing, in particular, different curing temperatures and curing times.

In the case of only physical curing of the coating composition, curing is preferably carried out in the range between 15 and 90 ° C for a period of time that is 2-48 hours. In this case, curing may thus differ from the self-evaporation and / or intermediate drying process by the merely the duration of conditioning of the coating film. In addition, the distinction between self-evaporation and intermediate drying does not matter. It should be possible, for example, to first coat films obtained by applying a physically curable coating composition, self-evaporation or intermediate drying at a temperature of 15-35 ° C for a period which is, for example, 0.5-30 minutes, and then withstand them at a temperature of 50 ° C for a period of 5 hours.

However, preferably coating compositions intended for use in the method in accordance with the invention, i.e. electroplating materials, aqueous basecoat materials, and topcoat materials are at least thermochemically curable, in particular preferably thermochemically curable and externally crosslinkable.

In principle, and in the context of the present invention, the curing of one-component systems is preferably carried out at temperatures of 100-250 ° C, preferably 100-180 ° C, for a period of 5-60 minutes, preferably 10-45 minutes, since these conditions are typically necessary to convert the coating film into a hardened coating film by a chemical crosslinking reaction. Accordingly, any phase of self-evaporation and / or intermediate drying that precedes curing is carried out at lower temperatures and / or for shorter periods of time. In this case, for example, self-evaporation can be carried out at a temperature of 15-35 ° C for a period which is, for example, 0.5-30 minutes, and / or intermediate drying can be carried out at a temperature, which is, for example, 40-90 ° C for a period that is, for example, 1-60 minutes

In principle, and in the context of the present invention, the curing of two-component systems is carried out at temperatures that are, for example, 15-90 ° C, preferably 40-90 ° C, over a period of 5-80 minutes, preferably 10-50 minutes . Accordingly, any phase of self-evaporation and / or intermediate drying that precedes curing is carried out at lower temperatures and / or for shorter periods of time. In this case, for example, the distinction between the terms “self-evaporation” and “intermediate drying” no longer matters. Any phase of self-evaporation and / or intermediate drying that precedes curing can be carried out, for example, at a temperature of 15-35 ° C for a period of time, which is, for example, 0.5-30 minutes, and at least at lower temperatures and / or for shorter periods of time than the cure that follows.

Of course, this does not exclude the curing of the two-component system at higher temperatures. For example, in step (4) of the method in accordance with the invention, which is described in detail below, the base coat or several base coatings hardens / hardens together with the topcoat. If both one-component and two-component systems are present in the films, for example, a one-component base coat and two-component coating varnish, then joint curing, of course, depends on the curing conditions that are necessary for the one-component system.

All temperatures given by way of example in the context of the present invention are understood as the temperature of the room where the coated substrate is. Which, therefore, does not mean that the base as such should have a certain temperature.

The method in accordance with the invention

In the method in accordance with the invention, a multilayer ink system is formed on a metal base (S).

In principle, useful metal substrates (S) include those containing or, which consist, for example, of iron, aluminum, copper, zinc, magnesium and their alloys, and steel in a wide variety of different forms and compositions. Preference is given to iron and steel substrates, for example, traditional iron and steel substrates, which are used in the automotive industry. The fundamentals can in principle be of any shape, which means that they can, for example, be simple sheets or other complex elements, such as, in particular, car bodies and parts thereof.

Prior to step (1) of the method according to the invention, the metal substrates (S) can be pretreated by a method known per se, i.e., for example, purified and / or provided with known conversion coatings. Cleaning can be carried out mechanically, for example, by grinding, grinding and / or polishing, and / or chemically by etching using surface etching in acid or alkaline baths, for example, using hydrochloric acid or sulfuric acid. Of course, purification using organic solvents or water-based cleansers is also possible. It is also possible to carry out pretreatment by applying conversion coatings, in particular by phosphating and / or chromating, preferably phosphating. Preferably, the metal substrates are at least coated with a conversion coating, in particular coated with a phosphate coating, preferably with zinc phosphating.

In step (1) of the method in accordance with the invention, the hardened plating (E.1) is obtained on a metal base (S) by electrophoretic deposition of the plating material (e.1) on the base (S) and subsequent curing of the plating material (e.1 )

The plating material (e.1), which is used in step (1) of the method in accordance with the invention, may be a cathodic or anodic plating material. Preferably, it is a cathode plating material. Electroplating materials have been known to those skilled in the art over a long period of time. These materials are water-based coating materials containing anionic or cationic polymers as binders. These polymers include functional groups that are potentially anionic, i.e. can turn into anionic groups, for example carboxylic acid groups, or functional groups that are potentially cationic, i.e. can turn into cationic groups, for example amino groups. The transformation for the charge of the groups is usually achieved through the use of suitable neutralizing agents (organic amines (anionic), organic carboxylic acids, such as formic acid (cationic)), which results in the formation of anionic or cationic polymers. Electroplating materials, as a rule, and, thus, preferably additionally contain traditional anti-corrosion pigments. In the context of the invention, preferred cathodic electroplating materials preferably comprise cathodic epoxy resins, in particular in combination with blocked polyisocyanates known as such. As an example, reference is made to the electroplating materials described in WO 9833835 A1, WO 9316139 A1, WO 0102498 A1 and WO 2004018580 A1.

Thus, preferably the plating material (e.1) is at least a thermochemically curable coating material, and in particular an externally crosslinkable material. The plating material (e.1) is preferably a one-component coating composition. Preferably, the plating material (e.1) as a binder contains a hydroxy-functional epoxy resin and a fully blocked polyisocyanate as a crosslinking agent. The epoxy resin is preferably cathodic, and in particular contains amino groups.

The electrophoretic deposition of such a plating material (e.1), which occurs in step (1) of the method in accordance with the invention, is also known. Application is carried out using electrophoresis. This means that the metal part to be coated is first immersed in a deep bath containing the coating material, and a direct current electric field is applied between the metal part and the counter electrode. In this way, the part functions as an electrode; non-volatile components of the plating material migrate to the base, due to the described charge of polymers that are used as binders, as a result of the action of an electric field, and precipitates on the base, forming a plating film. For example, in the case of cathodic plating, the base is thus attached as a cathode, and the hydroxide ions that are formed there by electrolysis of water neutralize the cationic binder, so that it deposits on the base and forms a plating layer. In this case, therefore, application is achieved by electrophoretic immersion.

After electroplating the electroplating material (e.1), the coated substrate (S) is removed from the bath, optionally washed with, for example, water-based washing solutions, then optionally self-evaporating and / or intermediate drying, and the applied electroplating material is finally solidified .

The applied electroplating material (e.1), (or the still not hardened applied electroplating) is subjected to self-evaporation, for example, at a temperature of 15-35 ° C for a period which is, for example, 0.5-30 minutes and / or subjected to intermediate drying at a temperature that is preferably 40-90 ° C, for a period which is, for example, 1-60 minutes

The plating material (e.1) deposited on the base (or applied yet not hardened plating) preferably hardens at temperatures that are 100-250 ° C, preferably 140-220 ° C, over a period of 5-60 minutes, preferably 10-45 minutes, resulting in a hardened plating (E.1).

The indicated conditions for self-evaporation, intermediate drying and curing are used in particular in the preferred case when the plating material (e.1) is a one-component thermochemically curable coating composition, as described above. However, this does not exclude such a possibility when the plating material is a coating composition that is cured in another way and / or when other conditions of self-evaporation, intermediate drying and curing are used.

The thickness of the hardened plating layer is, for example, 10-40 micrometers, preferably 15-25 micrometers. The entire thickness of the films indicated in the context of the present invention will be understood as the thickness of the dry films. Thus, the film thickness is the thickness of the hardened film in question. Thus, if it is indicated that the coating material is applied with a certain film thickness, it should be understood as such, which means that the coating material is applied so that the specified film thickness is achieved after curing.

In step (2) of the method in accordance with the invention, (2.1) a base coat (B.2.1) is obtained or (2.2) several base coatings (B.2.2.x) are applied directly on top of each other. Coatings are obtained by applying to the hardened plating (E.1) (2.1) an aqueous base coating material (b.2.1) directly to the hardened plating (E.1) or (2.2) sequentially applying several base coat materials to each other (b. 2.2.x).

Thus, the sequential application of several base coat materials (b.2.2.x) onto the hardened plating (E.1) is understood to mean that the first base coating material is first applied directly to the plating and then directly to a layer of the first base coating material is applied to the second base coating material. Any third base coat material is then applied directly to the layer of the second base coat material. This process can then be repeated in a similar manner to obtain additional layers of base coat material (i.e., fourth, fifth, etc. base coat).

Thus, the base coat (B.2.1) or the first base coat (B.2.2.x), after receiving it, is located directly on the hardened plating (E.1).

The terms "base coat material" and "base coat" in relation to the applied coating compositions and coating films obtained in step (2) of the method in accordance with the invention are used for greater clarity. The base coatings (B.2.1) and (B.2.2.x) do not harden separately, but harden together with the coating varnish material. Curing is thus carried out similarly to the curing of the so-called basecoat materials used in the standard method described in the introduction. In particular, the coating compositions that are used in step (2) of the method according to the invention do not harden separately, as are the coating compositions referred to as fillers in the context of the standard method.

The aqueous basecoat material (b.2.1), which is used in step (2.1), is described in detail below. However, it is preferably at least thermochemically cured, and in particular crosslinked under the influence of external factors. Preferably, the basecoat material (b.2.1) is a single component coating composition. Preferably, the base coating material (b.2.1) contains a combination of at least one hydroxy-functional polymer as a binder selected from the group consisting of polyurethanes, polyesters, polyacrylates and copolymers of said polymers, for example polyurethane-polyacrylates, and at least one melamine resin as a crosslinking agent.

The basecoat material (b.2.1) can be applied using methods of applying liquid coating compositions known to those skilled in the art, for example by immersion, coating by removing excess with a strip, spraying, applying with a roller or the like. Preference is given to application by spraying methods, for example, spraying using compressed air (pneumatic spraying), spraying without using air, spraying with high-speed rotation, spraying using electrostatic spraying (ESTA), optionally in combination with heated spraying, such as spraying with heated air. Most preferably, the basecoat material (b.2.1) is applied by pneumatic spray application or by electrostatic spray application. Thus, as a result of applying the base coating material (b.2.1), a base coating (B.2.1) is obtained, i.e. a layer of base coat material (b.2.1) applied directly to the plating (E.1).

After the application process, the applied base coating material (b.2.1) or the corresponding base coating (B2.1) is subjected to self-evaporation, for example, at a temperature of 15-35 ° C for a period which is, for example, 0.5-30 minutes, and / or intermediate drying at a temperature that is preferably 40-90 ° C, for a period that is, for example, 1-60 minutes First, self-evaporation is preferred at a temperature of 15-35 ° C for a period of 0.5-30 minutes, and then intermediate drying at a temperature of 40-90 ° C for a period of, for example, 1-60 minutes. In this case, the described conditions of self-evaporation and intermediate drying are applied, in particular, in the preferred case, when the base coating material (b.2.1) is a thermochemically cured one-component coating composition. However, this does not exclude the possibility when the base coating material (b.2.1) is a coating composition that is cured in another way and / or when other conditions of self-evaporation and / or intermediate drying are applied.

The basecoat (B.2.1) does not harden within step (2) of the method in accordance with the invention, i.e. preferably, it is not exposed to temperatures that are more than 100 ° C. for a period longer than 1 minute, and in particular it is preferably not exposed to temperatures that are more than 100 ° C. This is clearly and unambiguously seen from step (4) of the method in accordance with the invention, as described below. Since the base coat does not harden before step (4), it cannot harden at an earlier stage (2), since curing in step (4) will not be possible in this case.

The aqueous basecoat materials (b.2.2.x) that are used in step (2.2) of the process of the invention are also described in detail below. At least one of the basecoat materials (b.2.2.x) that are used in step (2.2), preferably all of the basecoat materials that are used in step (2.2), preferably are at least thermochemically cured, particularly preferably crosslinkable by external factors. Preferably, at least one base coating material (b.2.2.x) is a one-component coating composition; the foregoing is preferably applied to all basecoat materials (b.2.2.x). Preferably, at least one of the basecoat materials (b.2.2.x) contains a combination of at least one hydroxy-functional polymer as a binder selected from the group consisting of polyurethanes, polyesters, polyacrylates and copolymers of said polymers, for example, polyurethane-polyacrylates, and at least one melamine resin as a crosslinking agent. The foregoing is preferably applied to all basecoat materials (b.2.2.x).

Basecoat materials (b.2.2.x) can be applied by methods of applying liquid coating compositions known to those skilled in the art, for example, by dipping, coating by removing excess with a strip, spraying, applying with a roller or the like. Preference is given to applying using spray methods, for example, spraying using compressed air (pneumatic spraying), spraying without using air, using high-speed rotation, electrostatic spraying (ESTA), optionally in combination with heated spraying, for example using heated air (heated spray). Most preferably, the basecoat materials (b.2.2.x) are applied by pneumatic spraying and / or electrostatic spraying.

At the stage (2.2) of the method in accordance with the invention, the following system designation is proposed. Base coat materials and base coatings are generally designated as (b.2.2.x) and (B.2.2.x), while x may be replaced by other appropriate letters to indicate specific individual base coat materials and base coatings .

The first basecoat material and the first basecoat may be indicated as a, and the uppermost basecoat material and the uppermost basecoat may be indicated as z. The two indicated base coat materials or base coatings are always present in step (2.2). Any coatings located between them can be indicated sequentially with b, c, d, and so on.

Thus, as a result of applying the first base coat material (b.2.2.a), directly on the hardened plating (E.1), a base coat (B.2.2.a) is obtained. At least then one additional base coat (B.2.2.x) is applied directly to the base coat (B.2.2.a). If several additional basecoats are applied (B.2.2.x), then they are applied in the immediate sequence. For example, it is possible to apply exactly one additional base coat (B.2.2.x), in which case, in the resulting multi-layer paint system, the coating is located directly below the top coat (K), and thus may be referred to as a base coat (B.2.2.z) (see also figure 2). It is also possible, for example, to apply two additional basecoats (B.2.2.x), in which case the coating obtained directly on the base coat (B.2.2.a) may be indicated as (B.2.2.b), and the coating, as a result, located directly under the topcoat (K), in turn is referred to as (B.2.2.z) (see also figure 3).

Basecoat materials (b.2.2.x) may be the same or different. It is also possible to obtain several base coatings (B.2.2.x) with the same base coat material, and one or more additional base coatings (B.2.2.x) with one or more other base coat materials.

The applied basecoat materials (b.2.2.x) are typically self-vaporized and / or intermediate dried separately and / or jointly. Also, in step (2.2), preference is given to self-evaporation at a temperature of 15-35 ° C for a period of 0.5-30 minutes and intermediate drying at a temperature of 40-90 ° C for a period of, for example, 1 -60 min The sequence of self-evaporation and / or intermediate drying processes on a single or several base coatings (B.2.2.x) may vary depending on the requirements of a particular case. In particular, the preferred conditions for self-evaporation and intermediate drying described above are applied in the preferred case when at least one base coating material (b.2.2.x), preferably all base coating materials (b.2.2.x), contains (at) thermochemically curable one-component coating compositions. However, this does not exclude such a possibility when the base coating materials (b.2.2.x) are coating compositions that are cured in another way and / or when other conditions of self-evaporation and / or intermediate drying are applied.

Some preferred base coat sequence options for base coat materials (b.2.2.x) are explained as follows.

Option a) it is possible to obtain a first basecoat by applying the first basecoat material using electrostatic spraying (ESTA), and directly on the first basecoat to receive an additional basecoat by pneumatic spraying by spraying the same basecoat material. Although the two basecoats are thus based on the same basecoat material, it is obvious that the application is carried out in two stages, so that the basecoat material in question in the method according to the invention corresponds to the first basecoat material ( b.2.2.a) and additional base coat material (b.2.2.z). Prior to pneumatic application, the first basecoat is preferably self-vaporized for a short period of time, for example at a temperature of 15-35 ° C, for 0.5-3 minutes. Then, after pneumatic application, self-evaporation is carried out, for example, at a temperature of 15-35 ° C, for 0.5-30 minutes, and then intermediate drying is carried out at a temperature of 40-90 ° C for a period of 1-60 minutes. The described structure is also often referred to as a single layer base coat structure obtained by two applications (once using ESTA, once pneumatically). Since, at the same time, especially during the actual coating of PPO, the technical conditions of the enterprise where the staining takes place, suggest that there always passes a certain period of time between the first application and the second application, where the basis, for example, the car body, is brought to the desired physical condition when temperature, for example, 15-35 ° C, and, therefore, subjected to self-evaporation, the characteristic of this structure as a two-layer structure of the base coating is more understandable in a formal sense. The indicated variant of step (2.2) is preferably selected when the applied base coating material (b.2.2.x) (or two applied identical base coating materials (b.2.2.a) and (b.2.2.z)) contains effective pigments, as described below. While applying ESTA can guarantee good material transfer or only slight ink loss during application, the pneumatic application that follows gives good alignment of the effective pigments and therefore good properties of the overall ink system, in particular a high flop effect.

Option b) It is also possible to obtain the first base coat by applying directly to the hardened plating the first base coat material by electrostatic spraying (ESTA), subjecting said first base coat material to self-evaporation and / or intermediate drying, and then apply the second base coat using direct application of the second base coating material other than the first base coating material. In this case, the second basecoat material, also as described in option a), can be applied first by electrostatic spraying (ESTA) and then by pneumatic spraying, resulting in two directly on the first basecoat basecoats applied directly to each other, both of which are based on a second basecoat material. Between and / or after application, self-evaporation and / or intermediate drying, of course, are again possible. Option (b) of step (2.2) is preferably selected when the basecoat prepared for application of the paint, as described below, is first prepared directly on the plating and then, in turn, the basecoat material containing the effective pigments or coatings must be re-applied base coat material containing chromatic pigments. In this case, the first basecoat is based on a basecoat prepared for application of the paint, the second and third basecoats are based on a basecoat material containing effective pigments, or one additional basecoat is based on an additional basecoat material containing chromatic pigments.

Option c) It is also possible to obtain three basecoats sequentially applied to each other directly on the hardened plating, where in this case the basecoats are based on three different basecoat materials. For example, it is possible to apply a base coat prepared for application of paint, an additional coating based on a base coating material containing color pigments and / or effective pigments, and an additional coating based on a second base coating material containing color pigments and / or effective pigments. Between and / or after separate applications, and / or after all three applications, it is again possible to carry out self-evaporation and / or intermediate drying.

Thus, preferred embodiments in the context of the present invention include the preparation of two or three basecoats in step (2.2) of the process of the invention, and in this context, preference is given to the preparation of two directly applied basecoats using the same the same base coat material, and very particular preference is given to obtaining the first of these two base coatings using ESTA, and the second of these two base coatings using pneuma application. In this case, in the manufacture of a three-layer structure of the base coating, it is preferable that the base coating obtained directly on the hardened plating was based on the base coating material prepared for application of the paint. The second and third coatings are based either on the same base coating material, which preferably contains effective pigments, or on a first base coating material containing colored pigments and / or effective pigments, and a second base coating material different from it, containing colored pigments and / or effective pigments.

The base coatings (B.2.2.x) do not harden within the step (2) of the method in accordance with the invention, i.e. preferably, they are not exposed to temperatures of more than 100 ° C. for a period longer than 1 minute, and preferably they are not exposed to temperatures of more than 100 ° C. at all. The above is clearly and unambiguously seen from step (4) of the method in accordance with the invention, as described below. Since the base coatings do not harden before step (4), they cannot harden at an earlier step (2), since in this case curing in step (4) will not be possible.

The application of base coat materials (b.2.1) and (b.2.2.x) is carried out in such a way that the base coat (B.2.1) and the individual base coat (B.2.2.x), after curing, which was carried out in stage (4 ), have an thickness of individual coatings, which are, for example, 5-40 micrometers, preferably 6-35 micrometers, in particular preferably 7-30 micrometers. In step (2.1), a higher coating thickness is preferably obtained, which is 15-40 micrometers, preferably 20-35 micrometers. At stage (2.2), individual base coatings have, in any case, a relatively lower coating thickness, in this case, the general structure again has a coating thickness within the order of the value of one base coat (B.2.1). For example, in the case of two basecoats, the first basecoat (B.2.2.a) preferably has a coating thickness that is 5-35 and in particular 10-30 micrometers, and the second basecoat (B.2.2.z) preferably has a thickness coatings, which is 5-30 micrometers, in particular 10-25 micrometers.

In step (3) of the method according to the invention, a topcoat (K) is applied directly to (3.1) the base coat (B.2.1) or (3.2) to the uppermost base coat (B.2.2.z). The specified manufacture is carried out using a suitable application of the material of the coating varnish (k).

The coating varnish material (k) may, in principle, be any transparent coating composition known to one skilled in the art in this context. It includes transparent coating compositions based on water or solvents, which can be formulated either as single-component, or as two-component coating compositions, or as multi-component coating compositions. In addition, the powder materials of the topcoat are also suitable. Preference is given to solvent-based topcoat materials.

The coating lacquer materials used (k) in particular can be thermochemically and / or actinochemically curable. In particular, they are thermochemically curable and crosslinkable under the influence of external factors. Preference is given to two-component coating varnish materials.

Thus, transparent coating compositions usually and preferably contain at least one (first) polymer as a binder that has functional groups, and at least one crosslinking agent that has a functional group complementary to the functional groups of the binder. Preference is given to using at least one hydroxy-functional poly (meth) acrylate polymer as a binder and a polyisocyanate as a crosslinking agent.

Suitable coating varnish materials are described, for example, in WO 2006042585 A1, WO 2009077182 A1 or also in WO 2008074490 A1.

The coating material of the varnish (k) is applied using methods of applying liquid coating compositions known to those skilled in the art, for example by immersion, coating by removing excess with a strip, spraying, applying with a roller or the like. Preference is given to application using spray methods, for example, spraying using compressed air (pneumatic application) and electrostatic spray application (ESTA).

After application, the coating varnish material (k) or the corresponding coating varnish (K) is subjected to self-evaporation or intermediate drying at a temperature of 15-35 ° C for a period of 0.5-30 minutes. The conditions of self-evaporation and intermediate drying of this type are applied in particular in the preferred case when the material of the coating varnish (k) is a thermochemically cured two-component coating composition. However, this does not exclude the possibility when the material of the coating varnish (k) is a coating composition that is cured in another way and / or when other conditions of self-evaporation and / or intermediate drying are applied.

The coating varnish material (k) is applied so that the coating varnish, after curing, which is carried out in step (4), has a coating thickness of, for example, 15-80 micrometers, preferably 20-65 micrometers, in particular preferably 25 -60 micrometers.

You must take into account that the scope of the method in accordance with the invention does not exclude the application of additional coating compositions, for example, additional coating varnish materials, after applying the coating varnish material (k), and obtaining additional coating films in this way, for example, additional coating varnish. Also, such additional coating films are then cured in step (4), as described below. However, preferably only one coating varnish material (k) is applied, and then it hardens as described in step (4).

In step (4) of the method in accordance with the invention, the joint coating (4.1) of the basecoat (B.2.1) and the topcoat (K) or (4.2) of the basecoat (B.2.2.x) and the topcoat (K) are co-cured. .

Co-curing is preferably carried out at temperatures that are 100-250 ° C, preferably 100-180 ° C, over a period of 5-60 minutes, preferably 10-45 minutes. Curing conditions of the indicated type are applied in particular in the preferred case when the base coat (B.2.1) or at least one of the base coatings (B.2.2.x), preferably all base coatings (B.2.2.x), are based / based on thermochemically cured one-component coating composition. For this reason, as described above, such conditions are generally necessary to achieve curing, as described above, in said one-component coating composition. If the material of the coating varnish (k) is, for example, also a thermochemically curable one-component coating composition, the coating coating (K) of course also hardens under the indicated conditions. Obviously, the same is applied in the preferred case, when the material of the coating varnish (k) is a thermochemically cured two-component coating composition.

However, the above provisions do not exclude the possibility when the base coat materials (b.2.1) and (b.2.2.x) and the coating varnish materials (k) are coating compositions that are cured in another way and / or when other curing conditions are applied.

After stage (4) of the method in accordance with the invention is completed, the result is a multilayer ink system in accordance with the invention.

Base coat materials for use in accordance with the invention:

The base coating material (b.2.1) for use in accordance with the invention contains at least one specific reaction product (R), preferably only one reaction product (R).

The reaction products are unbranched. The unbranched reaction products can, in principle, be obtained by the conversion of difunctional reagents, in which case the binding of the reagents through the reaction of functional groups leads to the formation of unbranched, i.e. catenated, structure. Thus, if the reaction product, for example, is a polymer, then the polymer chain is unbranched. If the reaction product is, for example, a polyester, then the reagents used can be diols and dicarboxylic acids, in which case a number of ester bonds in the reaction product are unbranched. Preferably, during the manufacture of the reaction product (R), thus, mainly difunctional reagents are used. In particular, other reagents, such as monofunctional compounds, respectively, are preferably used only in small amounts, if at all. In particular, at least 80 mol% are used. %, preferably at least 90 mol. % and most preferably exclusively difunctional reagents are used. If additional reagents are used, they are preferably selected solely from the group of monofunctional reagents. However, it is preferred when exclusively difunctional reagents are used.

Useful functional groups of reagents include functional groups known to one skilled in the art in this context. Combinations of reagents that have suitable functional groups that can be linked to each other and, thus, can serve to produce a reaction product, are in principle also known. The same applies for the reaction conditions necessary for binding. Preferred functional groups of the reagents are hydroxyl, carboxyl, imino, carbamate, allophanate, thio, anhydride, epoxy, isocyanate, methylol groups, methylol ether groups, siloxane and / or amino groups, in particular preferably hydroxyl and carboxyl groups. Preferred combinations of functional groups that can be linked to each other are hydroxyl and carboxyl groups, isocyanate and hydroxyl groups, isocyanate and amino groups, epoxy and carboxyl groups and / or epoxy and amino groups; Moreover, during the selection of functional groups, it is necessary to ensure that the amount of hydroxyl functional groups and the acid number in the reaction product are obtained, as described below. Combinations of hydroxyl and carboxyl groups are very particularly preferred. In this embodiment, therefore, at least one reactant has hydroxyl groups, and at least one additional reactant has carboxyl groups. Combinations of dihydroxy-functional and dicarboxy-functional reagents are preferred. Carrying out the reaction of these reagents by a method known per se gives reaction products including ester bonds.

The reaction product is hydroxy-functional. It is preferred that the reactants are converted in such a way that the unbranched molecules formed have two terminal hydroxyl groups. This means that at each of the two ends of each obtained molecule there is one hydroxyl group.

The reaction product has an acid number that is less than 20, preferably less than 15, in particular preferably less than 10, and most preferably less than 5 mg KOH / g. Thus, it preferably has only a very small number of carboxylic acid groups. Unless explicitly stated otherwise, the acid number in the context of the present invention is determined in accordance with DIN 53402.

The described hydroxyl functionality, just like the low acid number, can be obtained, for example, by a method known per se, using suitable ratios of reagents that have suitable functional groups. Preferably, said dihydroxy-functional and dicarboxy-functional reagents are used during manufacture, and a suitable excess of the dihydroxy-functional component is used. In this context, it is necessary to further explain the following: for purely statistical reasons, the actual reaction, of course, does not immediately lead to the production of molecules that have, for example, the desired (di) hydroxyl functional group. However, the selection of suitable conditions, for example, an excess of dihydroxy-functional reagents, and carrying out the reaction until the desired acid number is obtained, will ensure that the reaction products or molecules that make up the reaction product are hydroxy-functional, at least average. One skilled in the art will know how to select the appropriate conditions.

During the manufacture of the reaction product, at least one compound (v) that is used or converted as a reagent has two functional groups (v.1) and an aliphatic or araliphatic hydrocarbyl radical (v.2), which is located between two functional groups, and has 12-70, preferably 22-55, and more preferably 30-40 carbon atoms. Thus, compounds (v) are composed of two functional groups and a hydrocarbyl radical. Useful functional groups, of course, include the functional groups described above, in particular hydroxyl and carboxyl groups. Aliphatic hydrocarbyl radicals are known as acyclic or cyclic, saturated or unsaturated, non-aromatic hydrocarbyl radicals. Araliphatic hydrocarbyl radicals are radicals that include both aliphatic and aromatic structural units.

,

, K.-F. Arndt, "Leitfaden der Polymercharakterisierung", Akademie-Verlag, Берлин, стр. 47-54, 1982, где в качестве калибровочного вещества применяли бензил).The number average molecular weight of the reaction products can vary over a wide range and ranges, for example, from 600 to 40,000 g / mol, in particular from 800 to 10,000 g / mol, most preferably from 1,200 to 5,000 g / mol. Unless explicitly stated otherwise, the number average molecular weight in the context of the present invention is determined by osmotic pressure. The determination is carried out using a vapor-phase osmometer (model 10.00 from Knauer) at a number of concentrations of the test component in toluene at a temperature of 50 ° C, with benzophenone as a calibration substance for determining the experimental calibration constant of the instrument used (in accordance with

,

, K.-F. Arndt, "Leitfaden der Polymercharakterisierung", Akademie-Verlag, Berlin, pp. 47-54, 1982, where benzyl was used as a calibration substance).

Preferred compounds (v) are dimeric fatty acids, or they are present in dimeric fatty acids. During the manufacture of the products of reaction (R), therefore, dimeric fatty acids are preferably, but not exclusively, used as compound (v). Dimeric fatty acids (which are also known for a long period of time as dimerized fatty acids or dimeric acids), as a rule, and particularly in the context of the present invention, are mixtures obtained by oligomerization of unsaturated fatty acids. They can be obtained, for example, by catalytic dimerization of unsaturated vegetable fatty acids, while the starting materials used, in particular, are unsaturated C ₁₂ -C ₂₂ fatty acids. The bonds are formed mainly using the Diels-Alder mechanism, and as a result, depending on the number and position of double bonds in fatty acids, which are used to obtain dimeric fatty acids, mixtures of mainly dimeric products are obtained that have cycloaliphatic, unbranched aliphatic, branched aliphatic as well as C ₆ aromatic hydrocarbon groups between carboxyl groups. Depending on the mechanism and / or any subsequent hydrogenation, aliphatic radicals may be saturated or unsaturated, and the fraction of aromatic groups may also vary. As a result, the radicals between the carboxylic acid groups contain, for example, 24-44 carbon atoms. For the manufacture, fatty acids which have 18 carbon atoms are preferably used, and thus the dimeric product has 36 carbon atoms. The radicals that attach the carboxyl groups of the dimeric fatty acids preferably do not have unsaturated bonds and do not have aromatic hydrocarbon radicals.

Thus, in the context of the present invention, C ₁₈ fatty acids are preferably used during manufacture. Particular preference is given to the use of linolenic, linoleic and / or oleic acid.

Depending on the reaction mode, the above oligomerization leads to the formation of mixtures containing mainly dimeric molecules, as well as trimeric molecules and monomeric molecules and other by-products. Purification is usually carried out by distillation. Commercially available dimeric fatty acids typically comprise at least 80% by weight of dimeric molecules, up to 19% by weight of trimeric molecules, and not more than 1% by weight of monomeric molecules and other by-products.

Preference is given to the use of dimeric fatty acids, which consist of at least 90% by weight, preferably of at least 95% by weight, most preferably of at least 98% by weight, of dimeric fatty acid molecules.

In the context of the present invention, preference is given to the use of dimeric fatty acids, which consist of at least 90% by weight of dimeric molecules, from less than 5% by weight of trimeric molecules, and from less than 5% by weight of monomeric molecules and other by-products. Particular preference is given to the use of dimeric fatty acids, which consist of 95-98% by weight of dimeric molecules, less than 5% by weight of trimeric molecules, and less than 1% by weight of monomeric molecules and other by-products. It is also particularly preferable to use dimeric fatty acids, which consist of at least 98% by weight of dimeric molecules, less than 1.5% by weight of trimeric molecules, and less than 0.5% by weight of monomeric molecules and other by-products. Fractions of monomeric, dimeric, and trimeric molecules and other by-products in dimeric fatty acids can, for example, be determined by gas chromatography (GC). In this case, before conducting GC analysis, dimeric fatty acids are converted to the corresponding methyl esters using the boron trifluoride method (see DIN EN ISO 5509), and then they are analyzed using GC.

Therefore, the main definition of "dimeric fatty acids" in the context of the present invention is that their manufacture includes oligomerization of unsaturated fatty acids. Said oligomerization results in the formation mainly, in other words, to some extent preferably at least 80% by weight, to a certain degree more preferably at least 90% by weight, even to a certain extent more preferably at least 95% by weight and in particular to a certain extent at least 98% by weight of dimeric products. The fact that oligomerization as a result leads to the formation of mainly dimeric products, including exactly two fatty acid molecules, confirms this statement, which is typical in any case. Consequently, an alternative expression for the corresponding term “dimeric fatty acids” is “a mixture containing dimerized fatty acids”. The use of dimeric fatty acids thus automatically ensures the use of difunctional compounds (v). The above also confirms the statement made in the context of the present invention that dimeric fatty acids are preferably used as compound (v). This is the result of the fact that compounds (v) are obviously the main component of the mixtures, which are referred to as dimeric fatty acids. Thus, if dimeric fatty acids are used as compounds (v), the above means that the indicated compounds (v) are used as appropriate mixtures with the above-described monomeric and / or trimeric molecules and / or other by-products.

Dimeric fatty acids to be used can be obtained as commercially available products. Examples include Radiacid 0970, Radiacid 0971, Radiacid 0972, Radiacid 0975, Radiacid 0976, and Radiacid 0977 from Oleon, Pripol 1006, Pripol 1009, Pripol 1012, and Pripol 1013 from Croda, Empol 1008, Empol 1061, and Empol 1062 from BASF SE, and Unidyme 10 and Unidyme TI from Arizona Chemical.

Further preferred compounds (v) are dimeric diols, or are present in dimeric diols. Dimeric diols have been known for a long period of time, and are also referred to in the scientific literature as dimeric fatty alcohols. They are mixtures which are obtained, for example, by oligomerization of unsaturated fatty acids or their esters and subsequent hydrogenation of acid groups or ester, or by oligomerization of unsaturated fatty alcohols. The starting materials that are used may be unsaturated C ₁₂ -C ₂₂ fatty acids or their esters, or unsaturated C ₁₂ -C ₂₂ fatty alcohols. Hydrocarbyl radicals that bind hydroxyl groups to dimeric diols are likewise defined as hydrocarbyl radicals that separate carboxyl groups of dimeric fatty acids.

For example, DE-1198348 describes their manufacture by dimerization of unsaturated fatty alcohols with compounds of basic alkaline earth metals at temperatures above 280 ° C.

They can also be obtained by hydrogenation of dimeric fatty acids and / or their esters, as described above, in accordance with the description of the accepted German patent application DE-B-1768313. Under the conditions described herein, not only the carboxyl groups of fatty acids are hydrogenated to hydroxyl groups, but also any double bonds that are still present in dimeric fatty acids or their esters are partially or completely hydrogenated. It is also possible to carry out hydrogenation in such a way that the double bonds are fully retained during the hydrogenation. In this case, unsaturated dimeric diols are obtained. Preferably, the hydrogenation is carried out in such a way that the double bonds are hydrogenated to a very significant extent.

Another method for producing dimeric diols involves the dimerization of unsaturated alcohols in the presence of diatomite / aluminum oxide catalysts and basic alkali metal compounds in accordance with the international patent application WO 91/13918.

Regardless of the described methods for the manufacture of dimeric diols, preference is given to the use of those dimeric diols that have been derived from C ₁₈ fatty acids or their esters, or C ₁₈ fatty alcohols. As a result of this method, mainly dimeric diols are formed, which have 36 carbon atoms.

Dimeric diols, which were obtained using the above industrial methods, always have different amounts of trimeric triodes and monofunctional alcohols. Typically, the proportion of dimeric molecules is more than 70% by weight, and the remainder are trimeric molecules and monomeric molecules. In the context of the invention, it is possible to use either said dimeric diols or purer dimeric diols that have more than 90% by weight of dimeric molecules. Particular preference is given to dimer diols which have more than 90-99% of the mass of dimer molecules, and in turn, among those indicated, those dimer diols whose double bonds and / or aromatic radicals were at least partially or completely hydrogenated . An alternative expression for the corresponding term "dimeric diols", therefore, is "a mixture containing dimers that can be obtained by dimerization of fatty alcohols." The use of dimeric diols thus automatically ensures the use of difunctional compounds (v). The above also confirms the statement made in the context of the present invention that dimeric diols are used as compounds (v). For this reason, compounds (v) are obviously the main component of the mixtures, which are referred to as dimeric diols. Thus, if dimeric diols are used as compounds (v), the above means that the indicated compounds (v) are used as appropriate mixtures with the above-described monomeric and / or trimeric molecules and / or other by-products.

Preferably, the average amount of hydroxyl functional groups of dimeric diols will be 1.8-2.2.

For this reason, in the context of the present invention, particular preference is given to the use of those dimeric diols that can be obtained by hydrogenation of the dimeric fatty acids described above. Very particular preference is given to those dimeric diols that consist of ≥90% by weight of dimeric molecules, ≤5% by weight of trimeric molecules, and ≤5% by weight of monomeric molecules and other by-products, and / or have a number of hydroxyl functional groups, which is 1.8-2.2. Particular preference is given to the use of those diols that can be obtained by hydrogenation of dimeric fatty acids, which consist of 95-98% by weight of dimeric molecules, less than 5% by weight of trimeric molecules, and less than 1% by weight of monomeric molecules and other by-products. Particular preference is also given to the use of those diols that can be obtained by hydrogenation of dimeric fatty acids, which consist of ≥98% by weight of dimeric molecules, ≤1.5% by weight of trimeric molecules, and ≤0.5% by weight of monomeric molecules and other by-products.

Dimeric fatty acids, which can be used to obtain dimeric diols, as already described above, depending on the reaction mode, contain both aliphatic and possibly aromatic fragments of the molecules. Aliphatic fragments of molecules can be further subdivided into unbranched and cyclic fragments, which in turn can be saturated or unsaturated. As a result of hydrogenation, aromatic and unsaturated aliphatic fragments of molecules can be converted to the corresponding saturated aliphatic fragments of molecules. Dimeric diols that can be used as component (v) may suitably be saturated or unsaturated. Dimeric diols are preferably aliphatic, in particular aliphatic and saturated.

In the context of the present invention, preference is given to the use of those dimeric diols that can be obtained by hydrogenation of carboxylic acid groups of preferably saturated aliphatic dimeric fatty acids.

Particular preference is given to the use of those diols that can be obtained by hydrogenation of dimeric fatty acids, which consist of ≥98% by weight of dimeric molecules, ≤1.5% by weight of trimeric molecules, and ≤0.5% by weight of monomeric molecules and other by-products.

More preferably, the dimeric diols have a hydroxyl number that is 170-215 mg KOH / g, even more preferably that is 195-212 mg KOH / g, and in particular 200-210 mg KOH / g, established in accordance with DIN ISO 4629. More preferably, dimeric diols have a viscosity that is 1500-5000 mPa · s, even more preferably 1800-2800 mPa s (25 ° C., Brookfield, ISO 2555).

Dimer diols for use, very particularly preferably include commercially available products Pripol ^® 2030 and in particular Priopol ^® 2033 from the company Uniqema, or Sovermol ^® 908 from the company BASF SE.

Preferred reaction products (R) can be obtained by reacting dimeric fatty acids with aliphatic, araliphatic or aromatic dihydroxy-functional compounds. Aliphatic compounds are non-aromatic organic compounds. They can be unbranched, cyclic or branched. Possible examples of compounds are those compounds which consist of two hydroxyl groups and an aliphatic hydrocarbyl radical. Also possible are compounds which, along with the oxygen atom that is present in the two hydroxyl groups, include additional heteroatoms, such as oxygen or nitrogen, in particular oxygen, for example in the form of ether bonds and / or ester bonds. Araliphatic compounds are those compounds that include both aliphatic and aromatic structural units. It is preferred, however, when the reaction products (R) are made by reacting dimeric fatty acids with aliphatic dihydroxy-functional compounds.

Aliphatic, araliphatic or aromatic dihydroxy-functional compounds preferably have a number average molecular weight which is 120-6000 g / mol, in particular preferably 200-4500 g / mol.

An indication of the number average molecular weight thus means that the preferred dihydroxy functional compounds are mixtures of dihydroxy functional molecules of different sizes. The dihydroxy functional compounds are preferably polyether diols, polyester diols or dimeric diols.

In the context of the present invention, it is preferred that dimeric fatty acids and aliphatic, araliphatic and / or aromatic, preferably aliphatic, dihydroxy-functional compounds react with each other in a molar ratio of 0.7 / 2.3 to 1, 6 / 1.7, preferably, which is 0.8 / 2.2-1.6 / 1.8, and most preferably, which is 0.9 / 2.1-1.5 / 1.8. As a result of the excess hydroxyl groups, hydroxy-functional reaction products are thus obtained which additionally have a low acid number. By the degree of excess of hydroxyl groups, it is possible to control the molecular weight of the reaction product. If only a small excess of the hydroxy-functional reagent is used, respectively, the result is products with a longer chain, since only in this case a substantial conversion of the acid groups present is guaranteed. In the case of a higher excess of hydroxy-functional reagent, respectively, the result is a reaction product with a shorter chain. The number average molecular weight of the reaction products, of course, is also affected by the molecular weight of the reagents, for example, preferably aliphatic dihydroxy-functional compounds. The number average molecular weight of the preferred reaction products can vary over a wide range and ranges, for example, from 600 to 40,000 g / mol, in particular from 800 to 10,000 g / mol, most preferably from 1,200 to 5,000 g / mol.

Preferred reaction products, therefore, can also be described as unbranched compounds of the block type A- (B-A) _n . In this case, at least one type of block is based on connection (v). Preferably, blocks B are based on dimeric fatty acids, i.e. compounds (v). Blocks A are preferably based on aliphatic dihydroxy functional compounds, in particular preferably aliphatic polyether diols, polyester diols or dimeric diols. In the latter case, the corresponding reaction product is thus based solely on compounds (v) bonded to each other.

Very particularly preferred reaction products can be obtained by reacting dimeric fatty acids with at least one aliphatic dihydroxy-functional compound of the general structural formula (I):

where R is a C ₃ -C ₆ alkylene radical, and n are respectively selected so that the compound of formula (I) has a number average molecular weight that is 120-6000 g / mol, with dimeric fatty acids and compounds of formula (I) used in a molar ratio of 0.7 / 2.3 to 1.6 / 1.7, and the resulting reaction product has a number average molecular weight of 600-40000 g / mol and an acid number of less than 10 mg KOH / g

In a very particularly preferred embodiment, as a result, n is selected in this case so that the compound of formula (I) has a number average molecular weight of 450-2200 g / mol, in particular 800-1200 g / mol. R preferably represents a C ₃ or C ₄ alkylene radical. An isopropylene radical or a tetramethylene radical is more preferred. Most preferably, the compound of formula (I) is polypropylene glycol or polytetrahydrofuran. Dimeric fatty acids and compounds of formula (I) are preferably used in this case in a molar ratio of 0.7 / 2.3 to 1.3 / 1.7. In this embodiment, the resulting reaction product has a number average molecular weight that is 1500-5000 g / mol, preferably 2000-4500 g / mol, and most preferably 2500-4000 g / mol.

Also very particularly preferred reaction products can be obtained by the reaction of dimeric fatty acids with at least one dihydroxy-functional compound of the general structural formula (II):

Where

R represents a divalent organic radical containing 2-10 carbon atoms,

R ¹ and R ² each independently represent straight chain or branched alkylene radicals that have 2-10 carbon atoms,

X and Y each independently represent O, S or NR ³ , where R ³ represents a hydrogen or alkyl radical that has 1-6 carbon atoms, and

m and n are respectively selected so that the compound of formula (II) has a number average molecular weight that is 450-2200 g / mol,

where components (a) and (b) are used in a molar ratio of 0.7 / 2.3 to 1.6 / 1.7 and the resulting reaction product has a number average molecular weight of 1200-5000 g / mol, and an acid value that is less than 10 mg KOH / g,

In structural formula (II), R is a divalent organic radical containing 2-10 carbon atoms, and preferably 2-6 carbon atoms. The radical R may, for example, be aliphatic, aromatic or araliphatic. The radical R, as well as carbon atoms and hydrogen atoms, may also include heteroatoms, for example, O or N. The radical may be saturated or unsaturated. R is preferably an aliphatic radical that has 2-10 carbon atoms, more preferably an aliphatic radical that has 2-6 carbon atoms, and most preferably an aliphatic radical that has 2-4 carbon atoms. For example, the radical R represents C ₂ H ₄ , C ₃ H ₆ , C ₄ H ₈ or C ₂ H ₄ —O — C ₂ H ₄ .

R ¹ and R ² each independently represent straight chain or branched alkylene radicals which have 2-10 carbon atoms, preferably 2-6 carbon atoms, and more preferably 3-5 carbon atoms. These radicals preferably include only carbon and hydrogen.

In compounds of structural formula (II), all n R ¹ radicals and all m R ² radicals may be the same. However, it is also possible when different types of radicals R ¹ and R ² are present. Preferably, all R ¹ and R ² radicals are the same.

Very particularly preferably, R ¹ and R ² are a C ₄ or C ₅ alkylene radical, in particular a tetramethylene or pentamethylene radical. In a very particularly preferred embodiment of the present invention, both radicals R ¹ and R ² are pentamethylene radicals.

X and Y each independently represent O, S or NR ³ , where R ³ represents a hydrogen or alkyl radical that has 1-6 carbon atoms. Preferably, X and Y each independently represent O or NR ³ ; more preferably each independently represents O and NH; most preferably, X and Y are O.

The thorn indices are suitably selected such that the compounds of structural formula (II) have a number average molecular weight of 450-2200 g / mol, preferably 500-1400 g / mol, more preferably 500-1200 g / mol.

Polyester polyols of general structural formula (I) can be prepared by the first procedure, where the HX-R-YH compounds act as the starting compounds, and the polyester chains with hydroxyl end groups are polymerized on the starting compound, by opening the ring hydroxycarboxylic acid lactone polymerization HO- R ^{1 is} COOH; and HO-R ^{2 is} COOH. Of course, it is also possible, by means of the second procedure, to first produce polyesters with alpha-hydroxy-gamma-carboxyl end groups, for example, by polymerization with the opening of the ring of lactones of hydroxycarboxylic acids HO-R ¹ -COOH and HO-R ² -COOH, or by polycondensation hydroxycarboxylic acids HO-R ¹ -COOH and HO-R ² -COOH. Alpha-hydroxy-gamma-carboxyl terminated polyesters, in turn, can then be reacted with HX-R-YH compounds via a condensation reaction to produce polyester diols intended for use in accordance with the invention.

Appropriate methods are described, for example, in the laid out description of the unattached application for German patent 2234265 "Hydroxylendstandige Polylactone" [Hydroxyl-terminal polylactones] of the applicant Stamicarbon N.V.

Dimeric fatty acids and compounds of formula (II) are preferably used in this case in a molar ratio of 0.7 / 2.3 to 1.3 / 1.7. In this embodiment, the resulting reaction product preferably has a number average molecular weight that is 1200-5000 g / mol, preferably 1200-4500 g / mol, and most preferably 1300-4500 g / mol.

Also very particularly preferred reaction products (R) can be obtained by reacting dimeric fatty acids with dimeric diols, where dimeric fatty acids and dimeric diols are used in a molar ratio of 0.7 / 2.3 to 1.6 / 1.7 and the resulting reaction product has a number average molecular weight that is 1200-5000 g / mol, and an acid number that is less than 10 mg KOH / g.

Preferred dimeric diols have already been described above. In this case, it is preferable when dimeric fatty acids and dimeric diols are used in a molar ratio of 0.7 / 2.3 to 1.3 / 1.7. The resulting reaction product in this case preferably has a number average molecular weight that is 1200-5000 g / mol, preferably 1300-4500 g / mol, and very preferably 1500-4000 g / mol.

From the above provisions it follows that the reaction products (R) can be obtained using the exclusive use of compounds (v). For example, it is possible to obtain reaction products from the use of the preferred dimeric fatty acids and dimeric diols described above. Both classes of compounds are compounds (v), or both classes of compounds are mixtures containing difunctional compounds (v). However, it is equally possible to obtain reaction products (R) by reacting compounds (v), preferably dimeric fatty acids, with other organic compounds, in particular compounds of structural formulas (I) and (II).

In the context of the present invention, it is preferable when 30-100 mol. % of at least one compound (v). If only compounds (v) are used, it is obvious that at least two compounds (v) are used.

The proportion of reaction products (R) is preferably in the range from 0.1 to 15% by weight, preferably 0.5-12% by weight, more preferably 0.75-8% by weight, based on, in each case, the total weight pigmented aqueous basecoat material (b.2.1).

If the content of the reaction products (R) is less than 0.1% by weight, then this can lead to when the improvement in impact resistance is no longer achieved. If the content is more than 15% by weight, then in certain circumstances flaws may arise, for example, incompatibility of the specified reaction product in an aqueous coating composition. Such incompatibility can be manifested, for example, in the uneven distribution of paint over the surface, as well as in the heterogeneity of the color or in the formation of plaque.

The reaction product in accordance with the invention, as a rule, is poorly soluble in aqueous systems. Because of this, it is preferably used directly during the manufacture of the pigment-dyed aqueous base coat material (b.2.1), and is not added to the finished coating composition only upon completion of manufacture.

The base coating material (b.2.1) intended for use in accordance with the invention preferably comprises at least one pigment. Pigments mean color and / or optical effect pigments that are known per se. Most preferably, it contains an optically effective pigment.

Lacke und Druckfarben, Georg Thieme Verlag, Штуттгарт, Нью Йорк, 1998, страницы 176 и 451. Термины "красящий пигмент" и "цветной пигмент" являются взимозаменяемыми, точно также, как и термины "оптически эффектный пигмент" и "эффектный пигмент".Such color pigments and effective pigments are known to those skilled in the art and are described, for example, in

Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, NY, 1998, pages 176 and 451. The terms “pigment pigment” and “color pigment” are used interchangeably, just like the terms “optically effective pigment” and “effective pigment”.

Preferred effect pigments, for example, are lamellar metallized effect pigments such as lamellar aluminum pigments, gold bronzes, oxidized bronzes and / or iron and aluminum oxide pigments, pearlescent pigments such as pearl essence, basic lead carbonate, bismuth oxychloride and / or metal oxide and mica pigments and / or other effect pigments such as plate graphite, plate iron oxide, multilayer effect pigments consisting of VD films and / or liquid crystal polymer pigments. Particular preference is given to lamellar metallized effect pigments, in particular lamellar aluminum pigments.

Traditional color pigments, in particular, include inorganic coloring pigments, such as white pigments, such as titanium dioxide, zinc white, zinc sulfide or lithopone; black pigments such as soot, black iron, or black spinel; chromatic pigments such as chromium oxide, chromium oxyhydrate green, cobalt green or ultramarine green, cobalt blue, ultramarine blue or magnesium blue, ultramarine violet or cobalt violet and magnesium violet, iron oxide red, cadmium sulfoselenide, molybdenum red or ultramarine red; iron oxide brown, mixed brown, spinel phases and corundum phases or chrome orange; or iron oxide yellow, titanonickel yellow, titanochrome yellow, cadmium sulfide, zinc and cadmium sulfide, chromium yellow or bismuth vanadate.

The proportion of pigments may preferably be in the range from 1.0 to 40.0% by weight, preferably 2.0-20.0% by weight, more preferably 5.0-15.0% by weight, based on each case , the total mass of the pigmented aqueous base coat material (b.2.1).

The aqueous base coating material (b.2.1) preferably also contains at least one polymer different from the reaction product (R) as a binder, in particular at least one polymer selected from the group consisting of polyurethanes, polyesters , polyacrylates and / or copolymers of said polymers, in particular polyurethane polyacrylates.

Preferred polyurethane resins are described, for example, in

- application for a German patent DE 19948004 A1, line 19 of page 4 - about line 29 of page 11 (prepolymer of polyurethane B1),

- application for a European patent EP 0228003 A1, line 24 of page 3 - line 40 of page 5,

- application for a European patent EP 0634431 A1, line 38 pages 3-8 line 9 pages, or

- international application for a patent for an invention WO 92/15405, line 35 of page 2 - line 32 of page 10.

Preferred polyesters are described, for example, in DE 4009858 A1 in column 6, line 53 to line 61 of column 7, and in column 10, line 24 to line 3 of column 13.

Preferred polyurethane-polyacrylate copolymers and their manufacture are described, for example, in WO 91/15528 A1, line 21 of page 3 - line 33 of page 20, and in DE 4437535 A1, line 27 of page 2 - line 22 of page 6.

The polymers described as binders are preferably hydroxy-functional. Preferably, the aqueous basecoat materials (b.2.1), as well as the reaction product (R), contain at least one polyurethane, at least one polyurethane-polyacrylate copolymer or at least one polyurethane and polyurethane-polyacrylate copolymer.

The proportion of additional polymers as a binder, preferably selected from at least one polyurethane, at least one polyurethane-polyacrylate copolymer, or at least one polyurethane and one polyurethane-polyacrylate copolymer, is preferably in the range from 0.5 to 20 , 0% by weight, more preferably in the range of 1.0-15.0% by weight, particularly preferably in the range of 1.0-12.5% by weight, based on, in each case, the total weight of the base material dyed with pigments by rytiya (b.2.1).

In addition, the basecoat material (b.2.1) preferably contains at least one conventional crosslinking agent, known per se. Preferably, it contains at least one aminoplast resin and / or a blocked polyisocyanate, preferably an aminoplast resin, as a crosslinking agent. Among amino resins, melamine resins are particularly preferred.

The proportion of crosslinking agents, in particular amino resin and / or blocked polyisocyanates, more preferably amino resin, among them preferably melamine resin, is preferably in the range of 0.5 to 20.0% by weight, more preferably in the range of 1.0-15 , 0% by weight, in particular preferably in the range of 1.5-10.0% by weight, based on, in each case, the total weight of the pigmented aqueous material of the base coat (b.2.1).

Preferably, the basecoat material (b.2.1) further comprises a thickener. Suitable thickeners are inorganic thickeners from the group of layered silicates. Lithium aluminum magnesium silicates are particularly suitable. In addition to organic thickeners, however, it is also possible to use one or more organic thickeners. These thickeners are preferably selected from the group consisting of thickeners based on a copolymer of (meth) acrylic acid and (meth) acrylate, for example, the commercially available product Rheovis AS SI30 (BASF), and from polyurethane thickeners, for example, the commercially available Rheovis PU 1250 (BASF company). The thickeners used differ from the polymers described above, for example preferred binders. Inorganic thickeners from the group of layered silicates are preferred.

The proportion of thickeners is preferably in the range from 0.01 to 5.0% by weight, preferably in the range of 0.02-4% by weight, more preferably 0.05-3.0% by weight, based on, in each case, the total mass of the pigmented aqueous base coat material (b.2.1).

In addition, the aqueous basecoat material (b.2.1) may also contain at least one additive. Examples of such additives are salts that can be thermally decomposed without residue, or substantially without residue, resins as binders that cure physically, thermally and / or using actinic radiation, and differ from the polymers already mentioned, additional crosslinking agents , organic solvents, reactive diluents, transparent pigments, fillers, soluble in molecular dispersion colorants, nanoparticles, light stabilizers, oxidation inhibitors, de ering agents, emulsifying agents, glidants, polymerization inhibitors, free radical initiators, adhesion promoters, product flow control agents, film-forming excipients, sack control agents (SCA), flame retardants, corrosion inhibitors, waxes, desiccants, biocides, as well as matting substances.

Suitable additives of the above type are known, for example, from

- applications for a German patent DE 19948004 A1, line 4 of page 14 - line 5 of page 17,

- German patent DE 10043405 C1, column 5, paragraphs [0031] to [0033].

They are used in conventional and known amounts. For example, their proportion may be in the range from 1.0 to 40.0% by weight, based on the total weight of the pigmented aqueous base coat material (b.2.1).

The solids content of the basecoat materials in accordance with the invention may vary in accordance with the requirements of a particular case. The solids content depends mainly on the viscosity that is necessary for application, in particular for application by spraying, and thus can be adjusted by a person skilled in the art in accordance with his or her general knowledge, optionally through a series of experimental studies.

The solids content of the base coat materials (b.2.1) is preferably 5-70% by weight, more preferably 8-60% by weight, most preferably 12-55% by weight.

By the content of solids (non-volatile fraction) is meant that mass fraction which remains as a residue after evaporation under the indicated conditions. In the present description, the solids content is determined in accordance with DIN EN ISO 3251. The above is carried out by evaporation of the base coating material at a temperature of 130 ° C for 60 minutes.

Unless otherwise specified, the specified research method is also used in order, for example, to establish or pre-determine the proportion of different components of the base coating material, for example, polyurethane resins, polyurethane-polyacrylate copolymer, in the total weight of the base coating material reaction (R) or a crosslinking agent. The solids content of the dispersion of the polyurethane resin determines the amount of polyurethane-polyacrylate copolymer, reaction product (R) or crosslinking agent to be added to the base coating material. Knowing the solids content of the dispersion and the amount of dispersion that are used in the base coating material, it is possible to identify or establish the proportion of the component in the overall composition.

The base coating material according to the invention is aqueous. The expression "water" in this context is known to the person skilled in the art. The phrase refers in principle to a base coating material that is not based solely on organic solvents, that is, does not include solvents exclusively on an organic basis as solvents, but instead, on the contrary, includes a significant fraction of water as a solvent. For the purposes of the present invention, “aqueous” should preferably be understood to mean that the coating composition in question, in particular the base coating material, has a proportion of water that is at least 40% by weight, preferably at least 45% by weight, very preferably at least 50% by weight, based on, in each case, the total amount of solvents present (i.e., water and organic solvents). In turn, preferably the proportion of water is 40-95% by weight, in particular 45-90% by weight, very preferably 50-85% by weight, based on, in each case, the total number of solvents present.

Of course, the same definition of “aqueous” is also applied to all additional systems described in the context of the present invention, for example, to the aqueous nature of electroplated materials (e.1).

Base coat materials (b.2.1) that are used in accordance with the invention can be obtained using mixing apparatuses and mixing methods that are common and known in the manufacture of base coat materials.

At least one of the basecoat materials (b.2.2.x) that are used in the method in accordance with the invention has the features essential in accordance with the invention, as described in the case of the basecoat material (b.2.1). In particular, this means that at least one of the basecoat materials (b.2.2.x) contains at least one aqueous dispersion containing at least one copolymer (CP). All preferred embodiments and features indicated in the description of the basecoat material (b.2.1) are preferably applied to at least one of the basecoat materials (b.2.2.x).

In the preferred variation (a) of step (2.2) described above of the method in accordance with the invention, where the two base coat materials used (b.2.2.x) are the same, both base coat materials (b.2.2.x) obviously have significant features in accordance with the invention, as described in the case of the basecoat material (b.2.1). In this embodiment, the basecoat materials (b.2.2.x) preferably contain effective pigments, as described above, in particular lamellar aluminum pigments. Preferred proportions are 2-10% by weight, preferably 3-8% by weight, based on, in each case, the total weight of the base coating material. However, the material may also contain additional pigments, i.e. in particular, chromatic pigments.

In the preferred variation (b) described above of step (2.2) of the method of the invention described above, the first basecoat material (b.2.2.a) is preferably applied first, which can also be referred to as a preparatory basecoat material. It serves as a primer for a basecoat film, which is then applied, and which can then optimally fulfill its function of imparting color and / or visual effect.

In a first separate embodiment, variations (b), a preparatory paint preparation of a base coat of the type indicated are substantially free of chromatic pigments and effective pigments. In particular, the base coat material (b.2.2.a) of this type contains less than 2% by weight, preferably less than 1% by weight, chromatic pigments and effective pigments, based on, in each case, the total weight of the pigmented aqueous material base coverage. It is preferably free of such pigments. In this embodiment, the paint preparation base coat material preferably contains black and / or white pigments, in particular preferably both types of said pigments. Preferably, it contains 5-20% by weight, preferably 8-12% by weight, white pigments and 0.05-1% by weight, preferably 0.1-0.5% by weight, black pigments, based on In each case, the total mass of the base coat material. The gray color, which is obtained as a result, which can be set with a different degree of brightness through the ratio of white and black pigments, is a separately adjustable base for the created base coat, which then follows, so that the color and / or visual effect that is provided by creating the basecoat material that follows, it can manifest itself optimally. Pigments are known to those skilled in the art and are also described above. A preferred white pigment in this case is titanium dioxide, a preferred black pigment is carbon black.

In the case of the basecoat material for the second basecoat, or for the second and third basecoat, in this embodiment of variation (b), preferably the same applies as indicated for the basecoat material (b.2.2.x) described in variation (a). In particular, preferably the material contains effective pigments. Both for the preparatory base coat material (b.2.2.x) and the second base coat material (b.2.2.x), preferably containing effective pigments, the essential features of the invention should be fulfilled, as described for the base material coatings (b.2.1). Of course, both basecoat materials (b.2.2.x) can also satisfy the indicated criteria.

In a second particular embodiment of the present invention, it is also possible if the base coat preparation material (b.2.2.a) contains chromatic pigments. The specified option can be applied by choice, in particular, when the resulting multilayer ink system should have a highly chromatic color tone, for example, very deep red or yellow. In this case, the preparatory coating material for the base coating (b.2.2.a) contains, for example, a proportion of chromatic pigments, which is 2-6% by weight, in particular red pigments and / or yellow pigments, preferably in combination with 3 15% by weight, preferably 4-10% by weight, white pigments. At least one additional basecoat material, which is then applied subsequently, also obviously contains the chromatic pigments described so that the first basecoat material (b.2.2.a) again serves as a preparatory paint application. In this embodiment, also, any single base coating material (b.2.2.x), several materials or each of them, can be a material that satisfies the features that are essential in accordance with the invention, as described in the case of the base coating material (b.2.1).

Also, in the preferred variation (c) of step (2.2) described above of the method in accordance with the invention, any single base coating material (b.2.2.x), several materials, or each of them, can be a material that satisfies features that are essential in accordance with the invention, as described in the case of a base coat material (b.2.1).

The method in accordance with the invention enables the manufacture of multilayer paint systems without a separate curing step. Despite this, the application of the method in accordance with the invention leads to multilayer paint systems that have excellent impact resistance, in particular, resistance to chips from impacts of small stones.

The impact resistance of colorful systems or their resistance to chips from impacts of small stones can be determined using methods known to specialists in this field. For example, one option is a crack resistance test in accordance with DIN 55966-1. Evaluation of respectively treated surfaces of paint systems in terms of the degree of damage and, therefore, in terms of the quality of resistance to chips from impacts of small stones, can be carried out in accordance with DIN EN ISO 20567-1.

The described method, in principle, can also be used to obtain multilayer paint systems on non-metallic substrates, for example, on plastic substrates. In this case, the base coating material (b.2.1) or the first base coating material (b.2.2.a) is applied to an optionally pretreated plastic base, preferably directly to an optionally pretreated plastic base.

The present invention is further illustrated by way of examples.

Examples

Description of the individual components and test methods used

Dimeric fatty acid:

The dimeric fatty acid that is used contains less than 1.5% by weight of trimeric molecules, 98% by weight of dimeric molecules and less than 0.3% by weight of fatty acid (monomer). It is made on the basis of linolenic acid, linoleic acid and oleic acid (Pripol ™ 1012-LQ- (GD), from Croda).

Polyester 1 (P1):

Made, as in example D, lines 37-59 of column 16 of the patent for invention DE 4009858 A. The corresponding solution of the polyester has a solids content of 60% by weight, using butyl glycol instead of butanol as a solvent, which means that those present the solvents are mainly butyl glycol and water.

Determination of number average molecular weight:

,

, K.-F. Arndt, "Leitfaden der Polymercharakterisierung", Akademie-Verlag, Берлин, стр. 47-54, 1982, где в качестве калибровочного вещества применяли бензил).The number average molecular weight was determined by osmotic pressure. The determination was carried out using a vapor-phase osmometer (model 10.00 from Knauer) at a number of concentrations of the test component in toluene at a temperature of 50 ° C, with benzophenone as a calibration substance for determining the experimental calibration constant of the instrument used (in accordance with

,

, K.-F. Arndt, "Leitfaden der Polymercharakterisierung", Akademie-Verlag, Berlin, pp. 47-54, 1982, where benzyl was used as a calibration substance).

The manufacture of the reaction product (R) intended for use in accordance with the invention

In a 4 liter stainless steel reactor equipped with a paddle stirrer, a thermometer, a condenser, a thermometer for determining the top temperature and a water separator, 2000.0 g of unbranched diol PolyTGF1000 (2 mol), 579.3 g of dimeric fatty acid (1 mol) and 51 g of cyclohexane was heated to a temperature of 100 ° C in the presence of 2.1 g of the oxide of di-n-butyltin (Axion ^® CS 2455 from the company Chemtura). Heating was slowly continued until condensation began. At the maximum temperature of the top, which was 85 ° С, the heating was continued step by step up to 220 ° С. The development of the reaction was monitored by determining the acid number. When an acid value of ≤3 mg KOH / g was reached, cyclohexane, which was still present, was removed by vacuum distillation. A viscous resin was obtained.

The amount of condensate (water): 34.9 g

Acid number: 2.7 mg KOH / g

Solids content (60 min at a temperature of 130 ° C): 100.0%

Molecular mass (osmotic pressure):

Mn: 2200 g / mol

Viscosity: 5549 mPa⋅s,

(set at 23 ° C using a Brookfield rotational viscometer, model CAP 2000+, rod 3, shear rate: 1333 s ^-1 )

The manufacture of an aqueous base coating material 1 not in accordance with the invention, which can be applied directly to the cathode plating as a color-providing coating

Making blue paste:

Blue paste was prepared from 69.8 parts by weight polyurethane dispersion akrilatirovannogo made as described in the international application for a patent for the invention of WO 91/15528, a binder dispersion A, 12.5 parts by weight Paliogen ^® Blue L 6482, 1 , 5 parts by weight of dimethylethanolamine (10% in demineralized water), 1.2 parts by weight of a commercially available polyether (Pluriol ^® P900 from BASF SE) and 15 parts by weight of deionized water.

Production of carbon black paste:

The carbon black paste was made from 25 parts by weight of a dispersion of acrylated polyurethane, made as described in the international patent application WO 91/15528, a binder dispersion A, 10 parts by weight of carbon black, 0.1 parts by weight of methyl isobutyl ketone, 1.36 parts by weight of dimethylethanolamine (10% in demineralized water), 2 parts by weight of a commercially available polyester (Pluriol ^® P900 from BASF SE) and 61.45 parts by weight of deionized water.

Production of mica dispersion:

A mica dispersion was prepared by mixing, using a mixing device, 1.5 parts by weight of a polyurethane-based graft copolymer prepared analogously to DE 19948004 - A1 (page 27, example 2) and 1.3 parts by weight of commercially available Mearlin Ext. Fine Violet 539V from Merck.

The manufacture of an aqueous base coating material II in accordance with the invention, which can be applied directly to the cathode plating as a color-providing coating

The aqueous material of the base coat II was prepared similarly to table A, except that instead of the polyester P1, the reaction product (R) was used. The appropriate solvents were replenished and exchanged based on the solids content of the respective binders.

Comparison of aqueous materials of the base coat I and II

To determine the resistance to chips from impacts of small stones, multilayer colorful systems were made using the following general method:

Covered by cathodic plating, a steel sheet measuring 10 × 20 cm served as a base.

First of all, a certain base coat material was applied pneumatically to said sheet. After the basecoat material was self-vaporized at room temperature for 1 minute, the basecoat material was subjected to intermediate drying in an air circulation oven at 70 ° C for 10 minutes. A conventional two-component coating varnish material was applied to the dried water-based basecoat. The resulting film of coating varnish was subjected to self-evaporation at room temperature for 20 minutes. Then, the hardening of the water-based basecoat and topcoat was carried out in an oven with air circulation at a temperature of 160 ° C for 30 minutes.

The multilayer colorful systems thus obtained were examined for adhesion as a result of impacts of small stones. For this purpose, in accordance with DIN 55966-1, a crack resistance test was performed. The results of the cracking resistance test were evaluated in accordance with DIN EN ISO 20567-1.

The results can be found in table 1.

The results confirm that the use of polyesters in accordance with the invention significantly increases the resistance to chips from impacts of small stones, compared with the aqueous base coating material 1.

The manufacture of an aqueous basecoat material 2 not in accordance with the invention, which can be applied directly to the cathode plating as a colorless coating

The components listed under the “aqueous phase” conditions in Table B were mixed together in that order to form an aqueous mixture. The combined mixture was then stirred for 10 minutes and, using deionized water and dimethylethanolamine, adjusted to a pH value of 8 and a viscosity of the ready-to-use material, which was 58 mPa⋅s under shear conditions of 1000 s ^-1 , what was found using a rotational viscometer (Rheomat RM 180, from the company Mettler-Toledo) at a temperature of 23 ° C.

Production of carbon black paste:

A carbon black paste was made from 25 parts by weight of a dispersion of acrylated polyurethane made as described in the international patent application WO 91/15528, a binder of dispersion A, 10 parts by weight of carbon black, 0.1 parts by weight of methyl isobutyl ketone, 1.36 parts by weight of dimethylethanolamine (10% in demineralized water), 2 parts by weight of a commercially available polyester (Pluriol ^® P900 from BASF SE) and 61.45 parts by weight of deionized water.

White paste making:

White paste was made from 43 parts by weight of a dispersion of acrylated polyurethane made as described in the international patent application WO 91/15528, a binder of dispersion A, 50 parts by weight of titanium rutile 2310, 3 parts by weight of 1-propoxy -2-propanol and 4 parts by weight of deionized water.

The manufacture of an aqueous base coating material 12 in accordance with the invention, which can be applied directly to the cathode plating as a colorless coating

The aqueous basecoat material 12 was made similar to Table B, except that instead of the polyester P1, the reaction product (R) was used. The appropriate solvents were balanced and exchanged based on the solids content of the respective binders.

The manufacture of an aqueous basecoat material 3 not in accordance with the invention, which can be applied directly to aqueous basecoat materials 2 and 12 as a color-providing coating

Making blue paste:

Blue paste was prepared from 69.8 parts by weight polyurethane dispersion akrilatirovannogo made as described in the international application for a patent for the invention of WO 91/15528, a binder dispersion A, 12.5 parts by weight Paliogen ^® Blue L 6482, 1 , 5 parts by weight of dimethylethanolamine (10% in demineralized water), 1.2 parts by weight of a commercially available polyester (Pluriol ^® P900 from BASF SE) and 15 parts by weight of deionized water.

Comparison of aqueous materials of base coat 2 and I2

To determine the resistance to chips from impacts of small stones, multilayer colorful systems were made using the following general method:

Covered by cathodic plating, a steel sheet measuring 10 × 20 cm served as a base.

Initially, the corresponding basecoat material — the aqueous basecoat material 2 or I2 — was applied to said sheet. After the base coating material was self-vaporized at room temperature for 4 minutes, an aqueous base coating material 3 was applied, then it was subjected to self-evaporation at room temperature for 4 minutes, and then it was subjected to intermediate drying in an air circulation oven at a temperature 70 ° C for 10 minutes A conventional two-component coating varnish material was applied to the dried water-based basecoat. The resulting film of coating varnish was subjected to self-evaporation at room temperature for 20 minutes. The water-based basecoat and topcoat were then hardened in an air circulation oven at 160 ° C for 30 minutes.

The multilayer colorful systems thus obtained were examined for adhesion as a result of impacts of small stones. For this purpose, in accordance with DIN 55966-1, a crack resistance test was performed. The results of the cracking resistance test were evaluated in accordance with DIN EN ISO 20567-1.

The results can be found in table 2.

The results confirm that the use of the polyester in accordance with the invention significantly increases the resistance to chips from impacts of small stones, in comparison with the aqueous material of the base coat 2.

The manufacture of an aqueous basecoat material 4 not in accordance with the invention, which can be applied directly to aqueous basecoat materials 2 or 12 as a color-providing coating

The components listed under the “aqueous phase” conditions in Table D were mixed together in this order to form an aqueous mixture. The combined mixture was then stirred for 10 minutes and, using deionized water and dimethylethanolamine, adjusted to a pH of 8, and to a viscosity of the material ready for application, which was 58 mPa⋅s under shear conditions of 1000 s ^-1 , as was established using a rotational viscometer (Rheomat RM 180 from Mettler-Toledo) at a temperature of 23 ° C.

Making red paste:

Red paste was made from 40 parts by weight of a dispersion of acrylated polyurethane manufactured as described in the international patent application WO 91/15528, a binder of dispersion A, 34.5 parts by weight of Cinilex® DPP Red, 2 parts by weight commercially available simple polyester (Pluriol ^® P900 from BASF SE), 3 parts by weight of 1-propoxy-2-propanol and 20.5 parts by weight of deionized water.

White paste making:

White paste was made from 43 parts by weight of a dispersion of acrylated polyurethane, manufactured as described in the international patent application WO 91/15528, a binder of dispersion A, 50 parts by weight of titanium rutile 2310, 3 parts by weight of 1-propoxy -2-propanol and 4 parts by weight of deionized water.

The manufacture of an aqueous base coat material I3 in accordance with the invention, which can be applied directly to aqueous base coat materials 2 or I2 as a color-providing coating

The aqueous material of the base coat I3 was prepared similarly to table D, except that instead of the polyester P1, the reaction product (R) was used. The appropriate solvents were balanced and exchanged based on the solids content of the respective binders.

Comparison of aqueous base coat materials 4 and I3 on aqueous base coat materials 2 and I2

To determine the resistance to chips from impacts of small stones, multi-layer colorful systems were made using the following general method:

Covered by cathodic plating, a steel sheet measuring 10 × 20 cm served as a base.

Initially, a specific basecoat material — an aqueous basecoat material 2 or I2 — was applied to said sheet. After the basecoat material was self-vaporized at room temperature for 4 minutes, an aqueous basecoat material 4 or I3 was applied, then it was self-vaporized at room temperature for 4 minutes, and then subjected to intermediate drying in an air circulation oven , at a temperature of 70 ° C for 10 minutes. A conventional two-component coating varnish material was applied to the dried water-based basecoat. The resulting film of coating varnish was subjected to self-evaporation at room temperature for 20 minutes. After that, the water-based basecoat and topcoat were hardened in an air circulation circulating oven at 160 ° C for 30 minutes.

The multilayer colorful systems thus obtained were examined for adhesion as a result of impacts of small stones. For this purpose, in accordance with DIN 55966-1, a crack resistance test was performed. The results of the cracking resistance test were evaluated in accordance with DIN EN ISO 20567-1.

The results can be found in table 3.

The results confirm that the use of polyesters in accordance with the invention significantly increases the resistance to chips from impacts of small stones. At the same time, it is understood that their combined use in colorless and color-providing coatings has the greatest impact.

Brief Description of the Figures

Figure 1:

Schematic formation of a multilayer paint system (M) in accordance with the invention, located on a metal base (S), and containing hardened plating (E.1) and a base coat (B.2.1), as well as a topcoat (K) that hardened together .

Figure 2:

Schematic formation of a multilayer paint system (M) in accordance with the invention, located on a metal base (S), and containing hardened plating (E.1), two base coatings (B.2.2.x), namely the first base coat (B. 2.2.a) and the top basecoat (B.2.2.z) located above it, and the topcoat (K), which hardened together.

Figure 3:

Schematic formation of a multilayer paint system (M) in accordance with the invention, located on a metal base (S), and containing hardened plating (E.1), three base coatings (B.2.2.x), namely the first base coat (B. 2.2.a), the base coat (B.2.2.b) located above it, and the top base coat (B.2.2.z), as well as the topcoat (K), which hardened together.

Claims (35)

1. A method of obtaining a multilayer paint system (M) on a metal basis (S), including (1) obtaining a hardened plating (E.1) on a metal base (S) by electrophoretic deposition of a plating (e.1) on the base (S) and subsequent curing of the plating (e.1), (2) obtaining (2.1) a base coat (B.2.1) or (2.2) of several directly applied basecoats (B.2.2.x) directly on the hardened plating (E.1) by (2.1) applying an aqueous base material coating (b.2.1) directly on the plating (E.1) or (2.2) applying on the plating (E.1) several materials of the base coating (b.2.2.x) directly on each other, (3) obtaining a topcoat (K) directly on (3.1) the basecoat (B.2.1) or (3.2) the top basecoat (B.2.2.x) by applying the topcoat (k) material directly to (3.1) the basecoat (B.2.1) or (3.2) the top basecoat (B.2.2.x), (4) co-curing (4.1) the base coat (B.2.1) and the topcoat (K) or (4.2) the base coat (B.2.2.x) and the topcoat (K), Where base coat material (b.2.1) or at least one of the base coat materials (b.2.2.x) contains at least one unbranched hydroxy-functional reaction product (R) which has an acid number of less than 20 mg KOH / g, the manufacture of which involves the use of at least one compound (v) comprising two functional groups (v.1) and an aliphatic or an araliphatic hydrocarbyl radical (v.2), which is located between functional groups and has 12-70 carbon atoms. 2. The method according to claim 1, where the functional groups (v.1) of at least one compound (v) are selected from the group consisting of hydroxyl groups and carboxyl groups. 3. The method according to p. 1 or 2, where during the manufacture of the product of reaction (R), dimeric fatty acids and / or dimeric diols are used as compound (v). 4. The method according to p. 1 or 2, where the reaction product (R) can be obtained by the reaction of dimeric fatty acids with aliphatic, araliphatic and / or aromatic dihydroxy-functional compounds, which have a number average molecular weight, which is 120-6000 g / the mole. 5. The method according to claim 1 or 2, wherein the aliphatic, araliphatic and / or aromatic dihydroxy functional compounds used are polyether diols, polyester diols and / or dimeric diols. 6. The method according to p. 1 or 2, where at least one reaction product (R) is selected from the group including reaction products that can be obtained by reaction of dimeric fatty acids with at least one aliphatic dihydroxy-functional compound of the general structural formula (I)

where R is a C ₃ -C ₆ alkylene radical, and n are respectively selected so that the compound of formula (I) has a number average molecular weight that is 120-6000 g / mol, with dimeric fatty acids and compounds of formula (I) used in a molar ratio of 0.7 / 2.3-1.6 / 1.7, and the resulting reaction product has a number average molecular weight of 600-40000 g / mol and an acid number of less than 10 mg KOH / g reaction products that can be obtained by reaction of dimeric fatty acids with at least one dihydroxy-functional compound of the general structural formula (II)

Where R represents a divalent organic radical containing 2-10 carbon atoms, R ¹ and R ² each independently represent straight chain or branched alkylene radicals that have 2-10 carbon atoms, X and Y each independently represent O, S or NR ³ , where R ³ represents hydrogen or an alkyl radical that has 1-6 carbon atoms, and m and n are respectively selected so that the compound of formula (II) has a number average molecular weight that is 450-2200 g / mol, where components (a) and (b) are used in a molar ratio, which is 0.7 / 2.3-1.6 / 1.7, and the resulting reaction product has a number average molecular weight, which is 1200-5000 g / mol, and an acid number that is less than 10 mg KOH / g, reaction products that can be obtained by reacting dimeric fatty acids with dimeric diols, where dimeric fatty acids and dimeric diols are used in a molar ratio of 0.7 / 2.3-1.6 / 1.7, and the resulting reaction product has a number average molecular weight, which is 1200-5000 g / mol, and an acid number, which is less than 10 mg KOH / g. 7. The method according to claim 1 or 2, where the base coating material (b.2.1) or at least one of the base coating materials (b.2.2.x), preferably all base coating materials (b.2.2.x), the binder additionally contains (at) at least one hydroxy-functional polymer selected from the group consisting of polyurethanes, polyesters, polyacrylates and copolymers of these polymers. 8. The method according to claim 7, where the base coating material (b.2.1) or at least one of the base coating materials (b.2.2.x), preferably all base coating materials (b.2.2.x), as a crosslinking material the agent further comprises (at) melamine resin. 9. The method according to PP. 1, 2 or 8, where the basecoat material (b.2.1) or at least one of the basecoat materials (b.2.2.x), preferably all basecoat materials (b.2.2.x), contains (at) at least one color pigment and / or effective pigment. 10. The method according to PP. 1, 2 or 8, where the basecoat material (b.2.1) or at least one of the basecoat materials (b.2.2.x) contains a metallized effect pigment, preferably lamellar aluminum pigment. 11. The method according to PP. 1, 2 or 8, where the basecoat material (b.2.1) or at least one of the basecoat materials (b.2.2.x), preferably all basecoat materials (b.2.2.x), are / are one-component coating compositions. 12. The method according to PP. 1, 2 or 8, where co-curing (4) is carried out at temperatures that are 100-250 ° C for a period of 5-60 minutes. 13. The method according to PP. 1, 2 or 8, where they receive (2.2) two base coatings (B.2.2.a) and (B.2.2.z), the aqueous base coat materials used for which (b.2.2.a) and (b.2.2. z) are the same and contain spectacular pigments. 14. The method of claim 13, wherein the basecoat material (b.2.2.a) is applied by electrostatic spraying and the basecoat material (b.2.2.z) by pneumatic application. 15. The method according to PP. 1, 2, 8 or 14, where at least two basecoats are obtained (2.2): the first basecoat (B.2.2.a) containing white pigments and black pigments directly on top of the plating (E.1) and subsequent basecoats (B.2.2.x) containing spectacular pigments. 16. The multilayer ink system (M), which was obtained by the method according to any one of paragraphs. 1-15.

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